title: Comparison of TLIF with rhBMP-2 versus no TLIF and higher posterolateral rhBMP-2 dose at L5-S1 for long fusions to the sacrum with sacropelvic fixation in patients with primary adult deformity.
abstract: METHODS
  Comparvative case series. Data was prospectively entered and retrospectively analyzed.
  
  
  OBJECTIVE
  To evaluate the need for distal lumbar interbody fusion when sufficient recombinant human bone morphogenetic protein-2 (rhBMP-2) is used posterolaterally at L5-S1 in long spinal constructs for adult deformity via costs and radiographical and patient-reported outcome comparisons.
  
  
  BACKGROUND
  Many authors and investigators have suggested that an interbody fusion is mandatory at L5-S1 with long fusion to the sacrum with sacropelvic fixation. Past studies have shown competitive fusion rates using rhBMP-2 versus iliac crest bone graft for long fusions. There are various advocates for anterior lumbar interbody fusion versus posterior lumbar interbody fusion versus transforaminal lumbar interbody fusion (TLIF). The optimal strategy remains elusive.
  
  
  METHODS
  Fifty-seven patients were studied at one institution. Thirty-one patients had no interbody fusion (NI group) with 20 mg of rhBMP-2 posterolaterally on 10 mL of carrier and 26 patients had TLIF at L5-S1 (TLIF group) with 6 mg of rhBMP-2 in the interbody space along with local bone graft and 6 mg of rhBMP-2 on carrier posterolaterally at L5-S1. Patients were followed for 24 to 87 months (mean follow-up, 3.92 yr). Demographics of the 2 groups were similar.
  
  
  RESULTS
  There were no detected nonunions at L5-S1 in either group. By our limited cost analysis, the expense of performing a TLIF at L5-S1 is higher than that of using extra rhBMP-2 posterolaterally at that segment. Improvement in outcomes scores, namely Scoliosis Research Society-22 and Oswestry Disability Index, were the same statistically in both groups. Blood loss was greater in the TLIF group than the NI group. There were no identified rhBMP-2 adverse events in either group.
  
  
  CONCLUSIONS
  Utilization of 20 mg of rhBMP-2 at L5-S1 has the potential to be less expensive than an interbody fusion in most patients having a primary long fusion for adult spinal deformity. The apparent fusion rates at L5-S1 were identical in both groups. Both strategies were successful in regard to improving patient outcomes and achieving apparent solid arthrodesis at the lumbosacral junction, which was the focus of this study.
  
  
  METHODS
  2.
authors.affiliation: *Division of Orthopaedics, Southern Illinois University School of Medicine, Springfield, IL; and †Department of Orthopedic Surgery, Washington University in St. Louis, St. Louis, MO.
authors.forename: RaʼKerry K
authors.initials: RK
authors.lastname: Rahman
authors.forename: Jacob M
authors.initials: JM
authors.lastname: Buchowski
authors.forename: Bradley
authors.initials: B
authors.lastname: Stephens
authors.forename: Ian G
authors.initials: IG
authors.lastname: Dorward
authors.forename: Linda A
authors.initials: LA
authors.lastname: Koester
authors.forename: Keith H
authors.initials: KH
authors.lastname: Bridwell
mesh_terms: D000328:Adult; D000368:Aged; D055396:Bone Morphogenetic Protein 2 / Q000627:therapeutic use*; D016025:Bone Transplantation; D003131:Combined Modality Therapy; D004305:Dose-Response Relationship, Drug; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008159:Lumbar Vertebrae / Q000000981:diagnostic imaging / Q000601:surgery*; D008161:Lumbosacral Region; D008297:Male; D008875:Middle Aged; D010388:Pelvis; D011859:Radiography; D011994:Recombinant Proteins / Q000627:therapeutic use; D012189:Retrospective Studies; D012447:Sacrum / Q000000981:diagnostic imaging / Q000601:surgery*; D012600:Scoliosis / Q000628:therapy*; D013123:Spinal Fusion / Q000379:methods*; D016212:Transforming Growth Factor beta / Q000627:therapeutic use*; D016896:Treatment Outcome
chemical_list: D055396:Bone Morphogenetic Protein 2; D011994:Recombinant Proteins; D016212:Transforming Growth Factor beta; C499469:recombinant human bone morphogenetic protein-2